cmd/run, pkg/podman: Make podman.InspectContainer() return a Container

Unmarshal the JSON from 'podman inspect --format json --type container'
directly inside podman.InspectContainer() to confine the details within
the podman package.

The JSON samples for the unit tests were taken using the default Toolbx
container on versions of Fedora that shipped a specific Podman and
Toolbx version.  This accounts for differences in the JSON caused by
different major versions of Podman and the way different Toolbx versions
set up the containers.

One exception was Fedora 28, which had Podman 1.1.2 and Toolbx 0.0.9,
which was the last Toolbx version before 'toolbox init-container' became
the entry point for all Toolbx containers [1].  However, the default
Toolbx image is no longer available from registry.fedoraproject.org.
Hence, the image for Fedora 29 was used.

The minimum required Podman version is 1.6.4 [2], and the Go
implementation has been encouraging users to create containers with
Toolbx version 0.0.17 or newer [3].  The versions used to collect the
JSON samples for the unit tests were chosen accordingly.  They don't
exhaustively cover all possible supported and unsupported version
combinations, but hopefully enough to be useful.

[1] Commit 8b84b5e
    containers@8b84b5e4604921fa
    https://github.com/debarshiray/toolbox/pull/160

[2] Commit 8e80dd5
    containers@8e80dd5db1e6f40b
    containers#1253

[3] Commit 238f245
    containers@238f2451e7d7d54a
    containers#318

containers#1490

Author: debarshiray

.codespellexcludefile

@@ -13,3 +13,4 @@
 		{"/var/lib/flatpak", "/run/host/var/lib/flatpak", "ro"},
 		{"/var/lib/systemd/coredump", "/run/host/var/lib/systemd/coredump", "ro"},
 		{"/var/log/journal", "/run/host/var/log/journal", "ro"},
+				"          \"ro\"," +

src/cmd/run.go

@@ -433,17 +433,16 @@ func runHelp(cmd *cobra.Command, args []string) {
 func callFlatpakSessionHelper(container string) error {
 	logrus.Debugf("Inspecting mounts of container %s", container)
 
-	info, err := podman.InspectContainer(container)
+	containerObj, err := podman.InspectContainer(container)
 	if err != nil {
 		return fmt.Errorf("failed to inspect entry point of container %s", container)
 	}
 
 	var needsFlatpakSessionHelper bool
 
-	mounts := info["Mounts"].([]interface{})
+	mounts := containerObj.Mounts()
 	for _, mount := range mounts {
-		destination := mount.(map[string]interface{})["Destination"].(string)
-		if destination == "/run/host/monitor" {
+		if mount == "/run/host/monitor" {
 			logrus.Debug("Requires org.freedesktop.Flatpak.SessionHelper")
 			needsFlatpakSessionHelper = true
 			break
@@ -526,30 +525,17 @@ func constructExecArgs(container, preserveFDs string,
 func getEntryPointAndPID(container string) (string, int, error) {
 	logrus.Debugf("Inspecting entry point of container %s", container)
 
-	info, err := podman.InspectContainer(container)
+	containerObj, err := podman.InspectContainer(container)
 	if err != nil {
 		return "", 0, fmt.Errorf("failed to inspect entry point of container %s", container)
 	}
 
-	config := info["Config"].(map[string]interface{})
-	entryPoint := config["Cmd"].([]interface{})[0].(string)
+	entryPoint := containerObj.EntryPoint()
+	entryPointPID := containerObj.EntryPointPID()
 
-	state := info["State"].(map[string]interface{})
-	entryPointPID := state["Pid"]
-	logrus.Debugf("Entry point PID is a %T", entryPointPID)
+	logrus.Debugf("Entry point of container %s is %s (PID=%d)", container, entryPoint, entryPointPID)
 
-	var entryPointPIDInt int
-
-	switch entryPointPID := entryPointPID.(type) {
-	case float64:
-		entryPointPIDInt = int(entryPointPID)
-	default:
-		return "", 0, fmt.Errorf("failed to inspect entry point PID of container %s", container)
-	}
-
-	logrus.Debugf("Entry point of container %s is %s (PID=%d)", container, entryPoint, entryPointPIDInt)
-
-	return entryPoint, entryPointPIDInt, nil
+	return entryPoint, entryPointPID, nil
 }
 
 func isCommandPresent(container, command string) (bool, error) {

src/meson.build

@@ -23,6 +23,7 @@ sources = files(
   'pkg/podman/container.go',
   'pkg/podman/errors.go',
   'pkg/podman/podman.go',
+  'pkg/podman/containerInspect_test.go',
   'pkg/shell/shell.go',
   'pkg/shell/shell_test.go',
   'pkg/skopeo/skopeo.go',

src/pkg/podman/container.go

@@ -18,38 +18,152 @@ package podman
 
 import (
 	"encoding/json"
+	"time"
 
 	"github.com/containers/toolbox/pkg/utils"
 )
 
 type Container interface {
 	Created() string
+	EntryPoint() string
+	EntryPointPID() int
 	ID() string
 	Image() string
 	Labels() map[string]string
+	Mounts() []string
 	Name() string
 	Names() []string
 	Status() string
 }
 
+type containerInspect struct {
+	created       string
+	entryPoint    string
+	entryPointPID int
+	id            string
+	image         string
+	labels        map[string]string
+	mounts        []string
+	name          string
+	status        string
+}
+
 type containerPS struct {
-	created string
-	id      string
-	image   string
-	labels  map[string]string
-	names   []string
-	status  string
+	created       string
+	entryPoint    string
+	entryPointPID int
+	id            string
+	image         string
+	labels        map[string]string
+	mounts        []string
+	names         []string
+	status        string
 }
 
 type Containers struct {
 	data []containerPS
 	i    int
 }
 
+func (container *containerInspect) Created() string {
+	return container.created
+}
+
+func (container *containerInspect) EntryPoint() string {
+	return container.entryPoint
+}
+
+func (container *containerInspect) EntryPointPID() int {
+	return container.entryPointPID
+}
+
+func (container *containerInspect) ID() string {
+	return container.id
+}
+
+func (container *containerInspect) Image() string {
+	return container.image
+}
+
+func (container *containerInspect) Labels() map[string]string {
+	return container.labels
+}
+
+func (container *containerInspect) Mounts() []string {
+	return container.mounts
+}
+
+func (container *containerInspect) Name() string {
+	return container.name
+}
+
+func (container *containerInspect) Names() []string {
+	return []string{container.name}
+}
+
+func (container *containerInspect) Status() string {
+	return container.status
+}
+
+func (container *containerInspect) UnmarshalJSON(data []byte) error {
+	var raw struct {
+		Config struct {
+			Cmd    []string
+			Labels map[string]string
+		}
+		Created   time.Time
+		ID        string
+		ImageName string
+		Mounts    []struct {
+			Destination string
+		}
+		Name  string
+		State struct {
+			PID    int
+			Status string
+		}
+	}
+
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return err
+	}
+
+	if len(raw.Config.Cmd) > 0 {
+		container.entryPoint = raw.Config.Cmd[0]
+	}
+
+	container.entryPointPID = raw.State.PID
+
+	created := raw.Created.Unix()
+	container.created = utils.HumanDuration(created)
+
+	container.id = raw.ID
+	container.image = raw.ImageName
+	container.labels = raw.Config.Labels
+
+	for _, mount := range raw.Mounts {
+		if mount.Destination != "" {
+			container.mounts = append(container.mounts, mount.Destination)
+		}
+	}
+
+	container.name = raw.Name
+	container.status = raw.State.Status
+	return nil
+}
+
 func (container *containerPS) Created() string {
 	return container.created
 }
 
+func (container *containerPS) EntryPoint() string {
+	return container.entryPoint
+}
+
+func (container *containerPS) EntryPointPID() int {
+	return container.entryPointPID
+}
+
 func (container *containerPS) ID() string {
 	return container.id
 }
@@ -62,6 +176,10 @@ func (container *containerPS) Labels() map[string]string {
 	return container.labels
 }
 
+func (container *containerPS) Mounts() []string {
+	return container.mounts
+}
+
 func (container *containerPS) Name() string {
 	return container.names[0]
 }
@@ -76,11 +194,14 @@ func (container *containerPS) Status() string {
 
 func (container *containerPS) UnmarshalJSON(data []byte) error {
 	var raw struct {
+		Command []string
 		Created interface{}
 		ID      string
 		Image   string
 		Labels  map[string]string
+		Mounts  []string
 		Names   interface{}
+		PID     int
 		State   interface{}
 		Status  string
 	}
@@ -89,6 +210,12 @@ func (container *containerPS) UnmarshalJSON(data []byte) error {
 		return err
 	}
 
+	if len(raw.Command) > 0 {
+		container.entryPoint = raw.Command[0]
+	}
+
+	container.entryPointPID = raw.PID
+
 	// In Podman V1 the field 'Created' held a human-readable string in format
 	// "5 minutes ago". Since Podman V2 the field holds an integer with Unix time.
 	// After a discussion in https://github.com/containers/podman/issues/6594 the
@@ -106,6 +233,7 @@ func (container *containerPS) UnmarshalJSON(data []byte) error {
 	container.id = raw.ID
 	container.image = raw.Image
 	container.labels = raw.Labels
+	container.mounts = raw.Mounts
 
 	// In Podman V1 the field 'Names' held a single string but since Podman V2 the
 	// field holds an array of strings